Plane bit



Feb. 26 1924. 1,484,861

- P. BASMAISON PLANE BIT Filed Aug. 15. 1922 4 B win ,F/Q 6 ALTTORNEYS.

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PIERRE BASMAISON, OF SAN FRANCISCO, CALIFORNIA.

PLANE BIT.

Application filed August 15, 1922.

To all whom it may concern:

Be it known that I, PIERRE BASMAISON, a citizen of the United States of America, and a resident of the city and county of San Francisco and State of California, have invented a new and useful Plane Bit, of which the following is a specification.

My invention relates to bits for woodworking tools and especially plane bits. One of the objects of my invention is to provide a plane bit having a replaceable cutting edge. Another object of the invention is the provision of a plane bit of the charac ter described in which the replaceable element when dull may be quickly discarded and another one easily inserted in its place and in which the structure is one of simplicity and strength.

My invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of my invention. It 18 to be understood that I do not limit myself to the showing made bythe said description as I may adopt variant forms of my invention within the scope of the claims.

Referring to the drawings: Figs. 1 and 2 are respectively perspective views of different forms of my invention. Portions of Fig. 2 are broken away to reveal the structure. Fig. 3 is a perspective view of the lower end of the cutter blade. Fig. 4 is a perspective view of the cutter. Fig. 5 is a side elevation of a modified form of my in vention. Portions of the figure are broken.

out to reduce the length thereof. Fig. 6 is a side elevation of the lower end of another modified form of my bit. Fig. 7 is a vertical sectional view thru a portion of a low angle block plane showing a modified form of my invention particularly adapted for such planes. Fig. '8 is a vertical sectional view thru another form of my invention.

Referring first to Fig. 1, my invention comprises a cutter blade 2 beveled at its lower end 3, preferably at an angle of about 25 degrees, and provided adjacent the end with a groove 4 extending transversely across the blade parallel to the beveled edge thereof. In Figs. 1, 2 and 3 the groove is shown extending into the surface of the blade at substantially right angles to the surface thereof. This groove constitutes a socket in which is seated a complementary member or flange 6 formed on the rear edge of the cutter 7, the front edge 8 of which is Serial No. 581,984.

sharpened and forms the cutting edge of the bit. The parts are proportioned so that the cutter may be pushed into position on the blade from the side, the flange 6 seating snugly in the groove and the sharpened edge 8 of the cutter overhanging'the edge of the blade suficiently to make the cutting edge effective.

Means are provided for clamping the cutter to the blade and such means also functions at its lower edge as a chip breaker. Such means comprisesa clamp plate 9. As will be observed from an inspection of the drawings the'cutter blade of my plane bit is quite similar to the cutter of the standard woodworkers plane and my clamp plate is also similar to the so-called cap of the double iron of such plane, being secured to the cutter blade by means of a screw 10 threaded into the clamp plate and passing thru a slot 11 in the blade in the same manner as in the case of the well known double iron. The lower portion 12 of the clamp plate is however ofiset somewhat and at the extreme lower end is curved inwardly again to, form a contact with the cutter 7 immediately back of the cutting edge, this distance being adjusted in accordance with the character of the work upon which the plane is used as will be understood by all woodworkers. In order to prevent the pressure of the clamp plate raising the rear end of the cutter, additional means are provided for pressing down the rear end so that no possible chattering or loosening of the cutter may occur.

A second clamp plate 13 is provided with lugs mat the side thereof, as shown in Fig. 1, adapted to interlock in slot-s 15 formed in the side of the main clamp plate. The second clamp plate extends downwardly between the ofi'set portion of the outer clamp plate and the cutter blade, overlying the inner edge of the cutter. Extending across the second clamp plate is a bead 16 adapted to be engaged by the under surface of the outer clamp plate so that when the screw 10 is tightened both clamp plates are pressed resiliently against the cutter, the outer clamp plate pressing on the cutter above or beyond the supporting edge of the cutter blade, and the inner clamp plate always pressing on the cutter well within the supporting edge of the cutter blade, these positions not being materially altered by ad ustment of the clamp plate to move the chip breaking edge of the outer clamp plate nearer or fartherffrom the cutting edge of the cutter. Any slight inequality in the alinement of the edges of the clamp plate is compensated for bytheresiliencejof the inner clamp plate. The resilient pressure of the clamp plates on the cutter when-the bit is not assembled in the plane is pret erably light enough to permit the cutter to be pushedtransversely out of its seat without loosening thescrew 10, but "when the --bit is assembled in the plane, the lower end is caught between the clamp of the plane and the frog, and the two clamp plates are then placed under'high pressure so that the cutter is securely held. 7 v j V v To change the 'cutterafter it has become dulled the bit is removed from the plane: and the cutter pulled out from the side, A

obvious that in an emergency the clamp plates may bemoved back and the cutter sharpened. .It is also contemplated that cutters ground to different bevels adapting themj'for various classes of work maybe used. It is'buft thewo'rk of an instant to substitute o'nefcutter for another so that perfect adaptability of the tool for the work in handm'ay'be had. a I V To facilitate removal of the cutter, notches 18 are formedin the clamp plates to expose the ends o'f the cutter, I V v jIn FigQ2 I have shown a modified form of my device which differs from thatalready explained-chiefly in the provision of asecond screw. 21 forindependently securing the inner clamp plate 22, which in this instance is shown riveted at its upper edgeto "the main clamp plate 23. In orderthatthe lower face of the bit may be flush adjacent its lower end, a beveled head screw seating in a beveled aperture in the'cntter blade 2 tjisuse'd, the screw passing thru aslotg25fin the inner, clamp plate and being threadedlinto a nut26 restingjon the inner clamp plate and lying in'a slot 27 formed in thejmain clamp plate. The slot 27 prevents the correspondingly shaped nut from turning, yet

with the slot 25 permits relative longitudinal movementbetwee'n the parts as made necessarv'b the adjustment of the clam lates y pl on the cutter.blade. A "screw 29' threaded into the clamp plate 23 serves to secure the clamp plates, and cutter blade together. In

this form' of my device, the inner clamp plate is'relied'on to hold the cutter when the bit is out of the plane, the outer clamp plate being sprung so that little or no pressure is exerted by it. It is obvious therefore 'thatafter removing the bit irom the plane,

plane, the plane clamp supplies the necessary pressureuponthe outer clamp plate to securely hold the cutter.

'Both'of the clamp plates, as shown in Figs. 1 and 2, are provided withan aperture 28 adapted toengage the adjusting stud of the plane mechanism.

In Fig. 5, I have shown another modified form of my device in which a. single clamp plate 31 is secured "to the cutter: blade'32 by the customary clamp screw 33." i In this case the cutter 34 is formed with two cutting edges, as shown, and provided with'a bead 36 running longitudinally across the'center of the cutter and adapted to engage in acorn plementary groove or socket'i ormed in the cutter blade. The unexposed or inner cutting edgeofthe cutter is engaged below the flange 37 extending transverselyacross the cutter blade and rigldly secured to orinte gral therewith. The engagement of the in ner edge of the cutter under the flange 37 prevents rising of the inner edge when the pressure ofthe clamp-plate is applied closei to the overhanging: edge of the cutter.

Fig. 6shows alsomewhat similar modifica tion'in which the "cutter is provided with a flange 38 making an obtuse angle with the body of the cutter and engaging in a simi larly disposed slot in the cutter blade 39. Clamp plate 41 is thes'ame asthat shown in Fig.5. Because of the angular engagement of the cutter flange in the blade, pressure of the single clamp is sutficient tohold the cuttersecurely. V v

In Fig. 7, I have shown an adaptation of my invention particularly suitable for block planes. In this case the'beveled' end of the cutter blade 42 is turned upwardly andthe cutter 43 is so formed as to overlie both the flat and beveled portions of the end of the cutter blade as shown. The cutter is pro-v vided with a flange 44 adapted toseat in-a correspondingly formed groove in'the cutter blade and is held in position byvthe' clampv a 1 45 ofthe plane mechanism- In Fig. 8, I have shown'still another embodiment of my invention inwhich the cutter blade 51 is formed with arabbet at its beveled end in which the cutter52 lies. In this case the cutter is a fiat strip ofsteel having preferably two areas 53 pressed outwardly from'its lower face to engage 'similar depressions' in the rabbet, .so that displacement of the cutter afterassembly under the clamp plate 54 is prevented. The clamp plate is provided with a fiat engaging surface 55 adapted to lie flush upon the cutter. When the bit is placed in the plane, the clamp of the plane pressing downwardly on the clamp plate insures a rigid holding of the cutter.

It will be noted that any of the forms oi my invention explained above may be used with a standard plane without alteration of the plane.

I claim:

1. A plane bit comprising a cutter blade formed with a socket adj aoent the lower edge thereof, a cutter having a portion complementary to said socket, a clamp plate overlying the blade and cutter, a second clamp plate overlying the blade and cutter, and means for drawing both clamp plates and the cutter blade together, said clamp plates bearing on said cutter on each side of the end of the said cutter blade.

2. A plane bit comprising a cutter blade formed with a socket adjacent the lower edge thereof, a cutter having a portion complementary to said socket, a clamp plate overlying the blade and bearing on the cutter beyond the edge of the blade, a second clamp plate overlying the blade and bearing on the cutter within the edge of the blade, and means for drawing the clamp plates and cutter blade together.

3. A plane bit comprising a cutter blade formed with a socket adjacent the lower end thereof, a cut-ter having a portion complementary to said socket, an outer clamp plate apertured to receive the adjusting stud of the plane and overlying the blade and cutter, an inner clamp plate secured to the outer clamp plate and overlying the blade and cutter, and means for independently clamping each plate and the blade together to secure the cutter on the blade, said outer and inner clamp plates respectively bearing on said cutter beyond and within the end of said cutter blade.

4. A plane bit comprising a cutter blade formed with a socket adjacent the lower end thereof, a cutter having a portion complementary to said socket, an outer clamp plate apertured to receive the adjusting stud of the plate and overlying the blade and cutter, an inner clamp plate overlying the blade and cutter and at its end remote from the cutter secured to the outer clamp plate, and clamping screws interposed between each clamp plate and the plane bit, said outer and inner clamp plates respectively bearing on said cutter beyond and within the end of said outter blade.

In testimony whereof, I have hereunto set my hand.

PIERRE BASMAISON. 

